Dust-cap.



R. M. PIERSON.

DUST CAP.

APPLICATION FILED AUG.6. 191s.

Patented Dec. 10, 1918.

UNITED STATES PATENT OFFICE.

ROBERT M. PIERSON, OF AKRON, OHIO, ASSIGNOR TO THE B. F. GOODRIOH COMPANY,

OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

DUST-CA1.

Application filed August 6, 1918.

felly into the space between the rim and the tire. My object is to provide an improved article of this class which may be applied and removed without the laborious operation of screwing it over a long thread. My

improved cap is particularlv adapted to be coupled to the familiar externally-threaded type of inflation-valve casing which is provided with longitudinal flats on opposite.

sides, but it may be used in any situation to which it is found applicable.

Of the accompanying drawings,

Figure 1 is a side elevation, partly in section, showing a preferred form of my improved cap applied to a pneumatic tire valve.

Fig. 2 is a section on the line 22 of Fig. 1.

Fig. 3 is a side elevation, partly in section showing a modification.

F Flg. 4 is a section on theline 44 of Referring at first to Figs. 1 and 2, 10 is a part of the wheel felly having a radial aperture 11 through which passes an inflation-valve casing 12 of the usual type formed with a screw thread 13 which is interrupted by flat portions 14 on two sides to prevent the rotation of said casing in the spreader lug at the tube (not shown). 15 is the usual nut engaging the thread 13 and abutting against the inner periphery of the felly for drawing said lug against the tire rim.

16 is my improved dust cap or protector which is made of soft vulcanized rubber (under which term I include semi-soft rubber), and is formed as a tubeclosed at the outer end and of general cylindrical form, but provided at and near the mouth of the cap with two flat portions 17 on opposite sides interposed between two arcuate portions. These flat portions correspondto the two flat surfaces 14 and may have any suitable Specification of Letters Patent.

Patented Dec. 10, 1918.

Serial No. 248,628.

location along the sides of the cap where they can engage the thread 13, although I prefer to locate them at the mouth of the cap. They might extend farther along the cap than shown, but are preferably made relatively short so as to avoid an undue 1 amount of friction when the cap is turned into its locking position. The mouth end of the cap acts as a gripper, and the size of its aperture is such that there is'a very slight clearance (or none at all) between said cap and the valve casing when the cap is in its unlocked position, as represented in the drawings.

In operation,-when the cap is positioned so that its fiat portions 17 register with the flat surfaces 14 on the valve casing, as indicated in Figs. 1 and 2, it may be freely moved longitudinally over said casing. To apply and locate the cap in its most advanced position so as to protect both the valve casing and the aperture 11 against the entrance of dirt and water, said cap is pushed into place until its inner end abuts against the nut 15, and is then given substantially a quarter-turn clock-wise from the position shown in Figs. 1 and 2 in order to cause both portions of the screw thread 13 on thevalve casing to bite into the flat portions 17 of the cap. This tends slight] to distort the month end of the cap, spreading the flat portions 17 farther apart and drawing together the intervening arcuate portions so that the cap grips the-valve casing, the resiliency of the rubber, combined with its frictional holding qualities, serving to hold the cap from accidentally unscrewing. While the flat portions 17 might be internally molded with portions of a screw thread complemental to thethread 13, it is preferred merely to rely upon the and stretching of the rubber by the metallic threaded portions of the valve casing.

In the modification shown in Figs. 3 and 4, I make the body part of the cap in the form ofa metal cylinder 18 closed at one end and formed near its mouth with two opposite holes 19. The locking member is a. sleeve 20 of vulcanized soft or semi-soft rubber inclosed within the mouth end of the metal cylinder and corresponding in function to the inner or mouth portion of the allrubber cap 16 shown in Figs. 1 and 2, said sleeve having'flat portions 17" corresponding to the flat portions 17, and being furfer to form the inner end of the sleeve 20 with an integral flange 22 to act as an end bearing or gasket under the edge of the metal body 18 when the cap is forced against the nut 15. In this form of the invention, the rigid tubular member 18 limits the amount of expansion of the sleeve 20 and hence tends to prevent any substantial permanent enlargement of the latter, such as may occur when the sleeve is made with a relatively-thin wall.

Various other changes may be made without departing from the scope of my invention.

' I claim:

1. The combination with a pipe-end formed externally with a mutilated screw thread, of a cap adapted to inclose said pipe-end and provided with an annular locking portion of relatively soft stretchable material, said cap being adapted in one rotary position thereof to move freely in a longitudinal direction over the pipe-end, and to interlock with the thread thereof by a turning movement of the cap.

2. The combination with a pipe-end having an external screw thread interrupted by longitudinally-extending plain portions, of a cap inclosi said pipe-end and having a soft-rubber gripper adapted to engage and disengage said thread by a rotary movement of the cap.

3. A cap for inflating valves havin an annular gripper composed of soft ru her and formed with a pair of opposite arcuate portions and a pair of intervening, opposite substantially flat portions.

4. The combination with a pipe-end having an external screw thread. interrupted by opposite longitudinally-extending flat surfaces, of a cap inclosing said pipe-end and having an annular soft-rubber gripper formed with opposite arcuate portions and intervening o posite flat portions freely movable longitu 'nally over the pipe-end when registered with the corresponding portions on the latter, the said flat portions being adapted to interlock with the thread on the pipe-end by a rotary movement of the cap.

5. A cap for inflating valves composed throughout of vulcanized soft rubber of tubular form, closed at one end and provided internally with opposite flat portions in its side walls adjacent to the mouth' of said cap.

6. The combination with a pipe-end having an external screw-thread interrupted by opposite longitudinally-extending flat surfaces, of a flexible rubber cap therefor having a tubular body adapted to surround but not grip said screw-thread, and a reduced mouth portion adapted to surround and grip the thread.

7. The combination of a wheel felly having a radial aperture, an inflating-valve casing projecting through said aperture and formed with an external screw thread interrupted by longitudinally-extending flat portions, a nut on the casing abutting against the inner riphery of the felly, and a cap having at its mouth end an annular soft-rubber gripping and packing portion closely embracing the valve casing and abutting against the nut, said gripping and packing portion having an opening corresponding to the cross-sectional shape of the valve-casing, the flat portions of the walls of said opening being adapted to grip the screw-thread on the valve casing when the ca is turned thereon.-

n testimony whereof I have hereunto set my hand this 5th day of August, 1918.

ROBERT M. PIERSON. 

